Preparing and Repairing Walls

Before painting, repair any defects in your drywall or plaster walls.

Preparing and Repairing Walls

Before you paint a wall, repair any defects and damage so you have a clean, flat, and unblemished surface for painting. Paint (especially semigloss and glossy coatings) does not hide defects in the wall surface; in fact, it usually makes them more noticeable.

First, remove any wallpaper or covering. Then use drywall compound to skim-coat any gouges or other damage created in the removal process. Let the compound dry and sand it when you sand the rest of the wall. Push on the wall to test whether the drywall has pulled away from the studs. If the wall gives in any places, drive screws into the studs to re-anchor it. Skim-coat the screws, also. Then repair any holes in the wall.

You don't actually have to remove sinks and other fixtures to paint the walls, but if you get them out of your way, your paint job will proceed much more smoothly and the surface will look much more attractive.

Prestart Checklist

About 20 to 30 minutes per square yard

Level, hammer, cold chisel, framing square, margin and mason?s trowels, dry-cutting saw (for plaster)

Cutting with utility knife, driving fasteners with cordless drill, troweling patching compound

Drywall, 1x3 lumber, 1-inch drywall screws, drywall tape, 2x4 lumber

Repairing damaged drywall: Step 1

Use a framing square to mark a rectangular area around a hole. Score the drywall on the lines, then cut through it with a drywall saw or utility knife. Pry out the damaged area or knock it into the wall recess.

Repairing damaged drywall: Step 2

Cut 1x3 boards about 6 inches longer than the area to be patched. Insert the boards into the recess and cinch them on one side to the rear of the drywall with 1-inch screws. Repeat for the other side. These cleats will keep the drywall patch from falling into the wall.

Repairing damaged drywall: Step 3

Cut a drywall patch of the same thickness as the rest of the wall and to the dimensions of the repair area. Place it in the recess against the cleats. Use 1-inch screws to fasten the patch to the cleats. Tape the joint around the patch with fiberglass-mesh drywall tape.

Repairing damaged drywall: Step 4

Finish the joints by applying a thin coat of drywall compound around the perimeter. Let this coat dry and apply a second coat with a wide drywall knife, feathering the edges until the surface is level with the surrounding wall. Prime this area when you spot-prime minor damage.

Repairing holes in plaster: Step 1

Cut damaged pieces from the hole with a wide cold chisel. Plaster is held together with a fibrous binder, so there may be small pieces clinging to the edge of the hole. Remove them and, if possible, angle the edges of the hole so they are wider next to the lath than at the surface.

Repairing holes in plaster: Step 2

Brush out the area or vacuum it. Using a spray bottle, moisten the edges of the hole and the lath with water. Don't soak the area; a moderate misting is sufficient.

Repairing holes in plaster: Step 3

Apply patching plaster to the damaged area with a wide putty knife, forcing the material slightly into the lath. If the thickness of the plaster is more than 1/2 inch, apply a thin coat first, let it dry, and apply another coat. Thick patches tend to crack if applied all at once.

Repairing cracked plaster: Step 1

If the crack is a hairline crack, clean it out with the edge of a putty knife or can opener and dust out the crack with an old paintbrush. Moisten the crack and apply spackling compound.

For wide cracks, use a can opener to scrape plaster from the rear of the edge, making it wider at its bottom than on the surface. This will help hold the patching compound more securely. Clean out the crack and vacuum or dust it with an old paintbrush.

Repairing cracked plaster: Step 2

Use a spray bottle to moisten the interior of the crack and pack joint compound or thinset into the recess with a wide putty knife or drywall knife. Press the compound into the recessed edges. When you have filled the crack, draw the putty knife across the surface to smooth it. Allow the compound to dry and reapply if necessary. Sand any rough or high spots smooth with medium-grit sandpaper.

Repairing large damaged areas in plaster: Step 1

Outline a rectangle larger than the damaged area and score the outline with a utility knife. Use a wide cold chisel to remove the plaster, working from the scored line to the center. Work in small sections; tap gently to avoid cracking the remaining wall. Measure the thickness of the plaster at the edge of the cutout area and, if necessary, attach 1/4-inch plywood strips to the lath so a 1/4-inch drywall patch will be flush with the surface.

Repairing large damaged areas in plaster: Step 2

Cut a drywall patch to the dimensions of the cutout and apply a 1/4-inch bead of construction adhesive to the shims or lath. Press the patch into the area. Starting at the corners, drive 1-inch drywall screws around the perimeter of the patch. Space the remaining screws about 6 inches apart. Tape the joints with fiber-mesh drywall tape and spread a thin, level coat of drywall compound over the tape. Sand level when dry.

Comments (3)
dbooth31coxne wrote:

I over sanded to the paper

2/6/2017 05:56:27 PM Report Abuse
anonymous wrote:

How to repair plaster walls?

12/29/2009 06:10:00 PM Report Abuse
darraugh1 wrote:

How do yoy repair cracks in sand finished walls and ceilings

11/21/2009 06:07:41 PM Report Abuse
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